The four systems of IA
Rosenfeld et al. (2015) divide IA into organisation (how to group), labelling (what to call), navigation (how to move) and search (how to find). If visual design is the interior, IA is the floor plan. Build it in users' language rather than departments, using methods such as card sorting (Spencer, 2009).
Broad and shallow, but careful on mobile
Kiger (1984) found broad, shallow menus faster and more accurate than deep ones, while Chae and Kim (2004) showed depth disorients more on small screens. A common mobile solution is four or five top-level items in bottom navigation and no more than two or three levels below. Miller's (1956) 7±2 concerns short-term memory and is not a valid limit for visible menus.
Users follow information scent
In information foraging theory (Pirolli & Card, 1999) users follow the scent of links and labels, and Chi et al. (2001) predicted paths from it. Prefer concrete labels such as 'Track delivery' or 'Request refund' over vague 'Services'. Design mobile search as a secondary route for those the structure fails.
FAQ
- Are IA and navigation the same?
- No; navigation is one visible part, while IA also covers organisation, labels and search.
- How many menu levels are ideal?
- There is no fixed number, but on mobile broad and shallow within two or three levels is common.
Sources reviewed: 2026-10-27
References
- Rosenfeld, L., Morville, P., & Arango, J. (2015). Information architecture: For the web and beyond (4th ed.). O'Reilly Media. The standard text covering organisation, labelling, navigation and search systems.
- Kiger, J. I. (1984). The depth/breadth trade-off in the design of menu-driven user interfaces. International Journal of Man-Machine Studies, 20(2), 201–213. Shows broad, shallow menus outperform deep ones.
- Chae, M., & Kim, J. (2004). Do size and structure matter to mobile users? An empirical study of the effects of screen size, information structure, and task complexity on user activities with standard web phones. Behaviour & Information Technology, 23(3), 165–181. Mobile study: deep structures confuse more on small screens.
- Pirolli, P., & Card, S. (1999). Information foraging. Psychological Review, 106(4), 643–675. Introduces information scent.
- Chi, E. H., Pirolli, P., Chen, K., & Pitkow, J. (2001). Using information scent to model user information needs and actions and the Web. In Proceedings of the SIGCHI Conference on Human Factors in Computing Systems (pp. 490–497). ACM. Models navigation paths using information scent.
- Miller, G. A. (1956). The magical number seven, plus or minus two: Some limits on our capacity for processing information. Psychological Review, 63(2), 81–97. Source of the common 'seven menu items' myth.
- Spencer, D. (2009). Card sorting: Designing usable categories. Rosenfeld Media. Covers building user-centred categories.